The present invention generally relates to improvements in a Picture Archiving and Communications System (PACS), and more particularly relates to a PACS performing multi-level image data processing.
A PACS is one of the latest generation of devices for medical diagnosis, storage, communication, and visualization. Typically, a PACS is implemented in conjunction with the medical imaging capabilities of hospital diagnostic equipment such as an X-ray imaging, ultrasound imaging, Magnetic Resonance Imaging (MRI), CAT scan, or other imaging device. The type of diagnostic imaging equipment is typically generically referred to as the imaging modality. Using an ultrasound system as an example, prior art ultrasound systems have typically been incarnated as stand-alone devices. Such stand-alone systems typically possess a display screen for observation of the ultrasonic diagnosis or are able to generate a printed image of a snapshot of the diagnosis. Such stand-alone systems typically were not able to electronically store images due to real-time processing constraints and storage capacity constraints.
However, recent improvements in the computing and networking fields have lead to the development of PACS systems, that is, systems that are able to store or archive the massive quantities of digital information that comprise each digital diagnostic image. Networking advancements have lead to the development of networks of sufficient bandwidth to transport such massive digital diagnostic images away from the stand-alone imaging device to a dedicated computer network, typically within the same facility. Once the data underlying the diagnostic image has been communicated to the dedicated network, the image may be stored, processed, reanalyzed, reproduced, or re-transmitted, for example. A PACS thus provides a large increase in flexibility of image treatment. An image of the patient may be stored and analyzed in several fashions, or may be transmitted to a specialist for review, for example.
However, because of the demands of processing huge-bandwidth images such as diagnostic images, present PACS systems operate in one of two ways. The first manner of operation positions a high-end workstation, such as an AMBER workstation as a gateway between the modality and the PACS. The workstation processes the digital data representing the diagnostic image received from the modality, typically in real time. The final processed image is then relayed to a storage medium within the PACS for later use. Typically, the processing employed by the workstation is in response to user-configured parameters such as frequency, contrast, or depth of the image. Typically, the workstation receives the raw digital data from the modality, processes the raw data to optimize the user-configured parameters, and then stores the final, processed image.
Also, typically, the massive amounts of digital data received by the workstation, once combined into a final image, are greatly reduced in size. However, once the final image has been supplied to the storage medium, very little further processing may be applied to the image. The amount of further processing is limited because the processing of the workstation typically eliminates data that is extraneous to the user-configured parameters. That is, for example, if an ultrasonic image at a depth of two inches within the patient is desired, the modality may still receive the entirety of the ultrasonic signal corresponding to a variable depth within the patient. The workstation typically receives the raw digital signal, synthesizes the desired image, and relays the image to the storage medium. If an image at a different depth is desired, a new diagnostic image must be performed. Because the workstation""s processing constraints dictate a high-end workstation, the first type of PACS systems are typically equipment-expensive. However, because the output of the workstation is typically a smaller image file, the first type of PACS systems are typically bandwidth-efficient. Bandwidth efficiency may often be preferable because it may allow the sharing or communication of the resultant digital images over commercial, non-dedicated networks such as the internet. However, the transmitted image may not be further manipulated.
The second type of PACS typically eliminates the workstation, or substitutes a reduced-application workstation that provides little processing, if any. In the second type of PACS system, the raw digital data is transported directly to a storage medium within the PACS without substantial processing. The raw digital data may then be retrieved from the storage medium for later non-real-time processing on a mid- to lower-end workstation that would be unable to process the raw digital information in real time. Although the second type of PACS may be less equipment-expensive with the elimination of the high-end workstation, the addition of the high-bandwidth communication channel directly to the PACS and the addition of a very fast storage medium represent significant cost. Also, the intra-networking of the PACS itself must be supplemented to reflect the vastly larger raw digital files that must be transported. In addition, the large, raw digital files are typically not externally transportable via less expensive non-dedicated communications channels, such as the internet, because of their size. Although the second type of PACS may be employed to generate processed digital images similar to the processed digital images supplied by the high-end workstation of the first type of PACS, because of the lesser scale of the workstation of the second type of PACS, the repeated formulation of such images may be quite time consuming. The formation of such images may become especially time-consuming if the PACS system is in use by more than one clinician or at more than one site, as is typically the case. The internal bandwidth constraints of the second type of PACS system may be especially severe if new raw data is being received from a modality at the same time as previously received data is being supplied to the workstation. Thus, although the second-type of PACS may provide a lower cost option, networking and bandwidth difficulties may make the second type of PACS inapplicable in a large clinical setting. In addition, while the raw digital data may reside in storage in the second type of PACS, and may thus be available to form images corresponding to differing user parameters, in a multi-user environment use of the second type of PACS system to perform multi-image analysis may not be practical.
As will be appreciated, the two types of PACS are not interchangeable without large-scale infrastructure expenditures. That is, to switch from one type of system to the other, either a high-end workstation must be procured or a high-bandwidth network must be installed.
Thus, a need has long existed for an improved PACS system providing improved imaging flexibility at a less expensive equipment and networking cost. A need has also long existed for a cost and practically effective system for allowing clinicians to perform multi-image analysis. Additionally, a need has long existed for a cost-effective system for transporting manipulatable image files through a commercial, non-dedicated network such as the internet.
The preferred embodiments of the present invention provide a Picture Archiving and Communications Systems (PACS) system having multi-level image data processing. The preferred embodiments of the present invention maximize computational efficiency, cost efficiency, network bandwidth efficiency and image manipulation flexibility. The preferred embodiments of the invention perform a first level of image data processing by partially preprocessing raw digital image data received from a modality at an acquisition workstation and then storing the partially processed image data on the PACS. Preferably, the preprocessing at the acquisition workstation is performed on frequency control related parameters while contrast control parameters remain unprocessed, although contrast control parameters may also be used. The partially processed image data may be retrieved later from the PACS and the processing completed using a second level of image data processing with user-selected and variable parameters at an image workstation. Fully processed images may then be stored in a PACS image data base. In addition, partially or fully processed imaged may be transmitted to an external network such as the internet.